EFFECT OF DIFFERENT LEVELS OF SUPPLEMENTARY IRRIGATION ON YIELD AND YIELD COMPONENT OF MAIZE (zea mays L) AT TEPPI, SOUTH WEST ETHIOPIA

Abstract

Maize (zea mays L) is one of the most important cereal crops grown in Ethiopia. Field experiment was undertaken on clay loam soil at Teppi national spice research center, Ethiopia during 2013/2014 cropping season with the objectives of investigating the effect of supplementary irrigation on yield and yield component of maize for achieving maximum crop yield in rain fed agriculture during belge season. The experiment was laid out in RCBD (Randomized Complete Block Design) with three replications. Treatments include seven levels of supplemental irrigation treatments and a control irrigation receiving no supplemental irrigation. The irrigation water was applied when the soil moisture depleted reached 55% of total available water (p=0.55). The supplemental irrigation levels had shown a highly significant (p<0.01) effect on grain yield of maize and gave increased water use efficiency. However, the treatments did not affect leaf area. The supplemental irrigation levels had also a significant (P<0.05) effect on days to tasseling, silking and days to maturity. The maximum yield of 67 q/ha was recorded from 100% ETc (Crop Evapotranspiration) which was not significantly different from 75% ETc and the minimum yield of 25q/ha was gained from rain fed treatment. In terms of water use efficiency rain fed treatment had the highest crop water use efficiency which has significantly different from all other treatment. Yield response factor (Ky) was separately calculated for the growing season and was found to be 1.25 the highest value and 1.05 the lowest value. Therefore, it is recommended that to apply 75% ETc which gave 6.16 ton/ha which improve WUE (Water Use Efficiency) without significant reduction of yield.